Controller for electric motors.



Patented Dec. I6, |902.

l E. 3. cAlcHoFF. CONTROLLER FOR ELECTRIC MOTORS.

(Applicafian med Aug. 1, 1901.)

(No ModeL) lNVEN-'TOR WITNESS-ES 5o maximum opposition being at thedesired 'is impracticable, whereas any method which tures ofconstruction and combination of parts UNITED STATES ATENT OEEIcE.

EUGENE R. CARICHOFF, OF EAST ORANGE, NEW JERSEY.

CONTROLLER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 715,975, dated December16, 1902.

Application iilefl August 1, 1901.

To a/ZZ whom t may concern.-

Beit known that I, EUGENE R. OAEICHOEE, a citizen of the United Statesof America, and a resident of East Orange, in the county of Essex andState of New Jersey, have invented certain new and useful Improvementsin Oontrollers for Electric Motors, of which the following is aspecification.

The present invention relates to controllers for electric motors, andmore especially to the means for intermittently driving thecontroller-cylinder.

It is very desirable in making contact with fixed brushes by means of acontroller-cylinder to approach and make contact with both certainty andrapidity.

It is the object of this invention to secure such advantage.

The iixed drive of a cylinder to secure the desired result requires arate of speed which permits contact to be .made or broken slowly provesunsatisfactory on account of burning due to poor contact and arcing dueto slow break.

For the purpose of securing the desired results my invention consists ofcertain feato be hereinefter described and then claimed.

In the accompanying drawings, Figure lis a perspective View of acontroller for electric motors, parts being broken away and omitted andshowing my invention applied thereto; and Fig. 2 is a detail view of thenotched wheel and pawl and correlated parts.

The controller-casing A is provided with bearings for the shaft B of thecontroller drum or cylinder C, which is provided with the stepped-Offcontacts d on its periphery, that make or break contact with the springcontact fingers or brushes d', xed to the casing in the usual manner.The shaft B is sufficiently extended so as to carry the notched wheel E,into the notches e of which the antifrictionroller f on the free end ofthe pawl F takes. A spring f acts on the pawl, tending to move it intoengagement with the notched wheel, the effect being that a variableopposition to the rotation of the drum is produced, the

points of contact-that is, where the pawl takes in the notches truly-andthe minimum Serial No. 70,517. (No model.)

being intermediate between these points, or, in other words, when thepawl is moving over the teeth formed between the notches. Pilotmotor Gtransmits by a worm g on its shaft g and a gear-wheel g2 rotary motionto a suitably-supported shaft H, the axis of which is in line with thatof shaft'B. Shaft H carries a crank 7i, the end of which extendsparallel with the shafts and by means of a helical torsion-spring I iscaused to be ,centered, so to speak, as that normally it lies midway be*tween abutments formed by pinsjj, locatedon that face of the notchedwheel which is presented toward Vthe crank. To this end, therefore, thecoils of said spring are placed over the projecting end ofshaft B, whilethe ends of the spring are bent out so as to extend approximatelyparallel with each other in the same direction, one end@` of said springbeing disposed on one side of an abutment or stop formed by fixed pinj2, located midway of and preferably in the same plane as the abutmentsor pinsjj, while the other end t" of the spring is disposed on the otherside of pin jz. The result is that pinj2 is located between the ends ofthe spring, which lie in contact with oppositesides of said pin. Springends 'L' t" protrude beyond the pin jg sufficiently so that the pin ofcrank 7i, may be positioned between them and whereby the crank isnormally held centrally between the abutments The action is as follows:The rotary force of the pilot-motor is transmitted to thecontroller-cylinder through the spring I, which moves under torsionbetween the abutments jj'. Owing to the retarding effect of the pawl Ein a notch of wheel E, the spring is coiled or placed under stress asthe pilot-motor revolves until an abutmentj orj' is reached, accordingto whether the spring end c' o r t" is advanced by the crank h,whereupon a positive movement is given to the controller-cylinder,rotating it until the force of the spring, still under stress, isgreater than the retarding action of the pawl, now at its minimum, whenthe controller-cylinder is thrown by the spring, due to the pressure ofthe spring end i or c" on the center stop or abutment/f2, until stoppedby the pawl at the next point of maximum retardation. The4 cylinder willhave thus been caused t0 advance more rap- IOO idly than the crank h ofthe pilot-motor, and the spring then becomes neutral. As the pilotmotorcontinues to advance the described action is repeated once for eachnotch e, securing 'an intermittent movement oi' the controller-cylinder,with a uniform motion of the pilotmotor. The pressure of the pawl may bevaried, and when properly adj usted to the strength of thedriving-spring it is impossible to stop the controller-cylinder at anypoint giving other than full contact or full open circuit to any brush.

It will be seen that by the described intermittent drive the contactsare made with certainty and quickness.

That I claim as new, and desire to secure by Letters Patent, is-

l. In a controller for electric motors, the combination with thecontroller-cylinder, and driving means for imparting motion thereto, ofa notched wheel and spring-pawl for intermittently and yieldinglyretarding the rotation of the cylinder, and a torsion-spring fortransmitting in either direction to the cylinder quicker impulses ofmotion than those given by the driving means, a portion of the drivingmeans lying normally between and adapted to engage either end of thespring to yplace it under tension; substantially as described.

2. In a controller for electric motors, the combiuation,with thecontroller-cylinder, the pilot-motor, and a shaft geared with that ofthe pilot-motor and provided with a drivingcrank, of means forintermittently retarding the rotation of the controller-cylinder, and atorsion-spring coiled around the shaft of the controller'cylinder for imparting quicker impulses of motion to the same than those given by saiddriving-crank, such spring being set for action by the operation of saidcrank on one end thereof and, when permitted to exert its force, acting,by its other end to throw the controller-cylinder, substantially asdescribed.

3. In a controller for electric motors, the combination, with thecontroller-cylinderprovided with three abutments on a portion thereon,and driving means for imparting positive motion to the cylinder, ofmeans for intermittently retarding the rotation of thecontroller-cylinder, and a spring the' ends of Which normally restagainst the middle abutment and receive between them a portion of thedriving means so as to center the same, while said ends may be movedagainst the other abutments, whereby quicker impulses of motion, ineither direction, may be imparted to the controller-cylinder than thosegiven by the positively-acting driving means, substantially asdescribed.

4:. In a controller for electric motors, the com bination,with thecontroller-cylinder provided with three abutments on a portion thereof,and driving means for imparting positive motion to the cylinder, ofmeans for intermittently retarding the rotation of the cont-rollercylinder, and a torsion spring coiled around the shaft of thecontroller-cylinder for imparting quicker impulses of motion to the samethan those given by said driving means, the ends of said spring normallyresting against the middle abutment and receiving between them a portionof the driving means so as to center the same, which said ends may bemoved against the other abutments, substantially as described.

5. In a controller for electric motors, the combination,with thecontroller-cylinder, and driving means for imparting positive motionthereto, of means for intermittently retarding the rotation of thecontroller-cylinder, and a spring the ends of which both bear against aportion on the controller-cylinder, and thereby neutralize the effect ofthe spring when the parts are at rest, a portion of such driving meansbeing arranged to act on either end of said spring, and permit it toexert its full force, when the retarding influence is overcome,substantially as described.

Signed by me in New York city the 31st day of July, 1901.

EUGENE R. CARlCI-IOFF. 1Witnesses:

GEO. L. WHEELocK, SAMUEL W. BALOH.

